DO NOT MERGE: Support converting X.509 cert into a verity public key

fs_mgr requires an RSA public key in mincrypt format for verifying
dm-verity hash tables. Add support for extracting public keys from
existing X.509 certificates and converting it into mincrypt format
for use with fs_mgr.

Bug: 15984840
Bug: 18120110
Change-Id: Ibcdca116cdc32dfa33d8f5636ec728244cbf6fd5
(cherry picked from commit 82d824a6b5028930abd87ecd870924c72d3b3931)
1 file changed